The present invention generally relates to a crosspoint switch.
A crosspoint switch is an electronic system that includes a collection of switches arranged in a matrix configuration. A crosspoint switch has multiple input and output signal paths that cross the matrix. A switch (called a “point cell” herein) is provided at intersections between the input and output pathways. When a point cell is activated, the point cell outputs a signal that is present on its input to its output. Thus, the crosspoint switch may communicate signals from its inputs to its outputs. Crosspoint switches find application in computer networks, communications and telephony networks, and other data routing applications.
The matrix may be controlled to propagate signals in a variety of ways. In one configuration, each input signal may be output to a single output. Thus, a single point cell on each input pathway may be activated, which causes its respective input signal to be output to a respective output pathway. In another configuration, a single input signal may propagate to all outputs of the crosspoint switch. In this configuration, all point cells on an input pathway may be activated, which causes the signal on the input pathway to be output to all output pathways. And, of course, the matrix may be controlled that a single input may be output to a subset of output pathways and other inputs may be output to other outputs that are not members of the subset being used by the first input pathway. Thus, crosspoint switches must be able to accommodate a variety of switching configurations on a dynamic basis.
In order for a crosspoint switch to reliably communicate signals from its inputs to its outputs, sufficient bandwidth must be maintained on the input and output pathways. If the bandwidth on the pathways is too low relative to the data rate, then intersymbol interference (ISI) will corrupt the signals. As the number of inputs and/or outputs of a crosspoint switch increases, the capacitance on the pathways and the power required by the buffers driving the pathways tend to increase linearly for a given bandwidth. Additionally, for a given data rate and power, the number of crosspoint connections is limited by the bandwidth on the pathways. Manufacturing buffers capable of driving the pathways with sufficient bandwidth is generally limited by the capability of the solid-state technology manufacturing process and maximum allowable power consumption.
Therefore, the inventor recognized a need in the art for a scalable crosspoint switch having reduced power consumption.